Printing-telegraph system



v '(No Model.) I

s Sheets-B11661; 1. J. E. WOOD-BRIDGE. PRINTING TELEGRAPH SYSTEM.

No. 549,179. Patented Nov. 5, 1895.

' v I f L No. 549,179.

no Model.) 3 Sheets-Sheet 2.

- "J. E. WOODBRIDGE. PRINTING TELEGRAPH SYSTEM.

Patented Nov. 5 1895.

(-No Model.) 3 SheetsSheet 3.

J. E. 'WOODBRIDGE. PRINTING TELEGRAPH SYSTEM.

No. 549,179. Patented Nov. 5, 1895.

WW I 3 UNITED STATES 'v PATENT OFFICE.

JONATHAN E. IVOODBRIDGE, OF DULUTH, MINNESOTA.

PRINTING-TELEGRAPH SYSTEM.

SPECIFICATION forming part of Letters Patent No. 549,179, dated November5, 1895.

Application filed January 29, 1895. Serial No. 536,581. (No model.)

To all whom it may concern.-

Be it known that I, JONATHAN E. WooD- BRIDGE, of Duluth, Minnesota, haveinvented a new and useful Improvement in Printing- Telegraph Systems,which improvement is fully set forth in the following specification.

This invention relates to printing telegraphs, and more particularly tosystems employing a type-wheel having characters arranged on itsperiphery and adapted to be turned to bring any desired character to theprinting position.

' The general objects of my invention are, first, to increase therapidity of transmission by diminishing the movements necessary and thetime required to bring the type wheel to the printing position, and,second, to simplify greatly the printing mechanism and other parts ofthe system.

More specifically, the objects sought and results attained (amongothers) by my invention are the following First, to operate over onewire with currents of uniform duration and uniform strength, avoidingthe uncertainties and complications attending the use of extra strengthand variable-length currents.

Second, to avoid the use of synchronism, unison devices, andspecially-constructed relays.

Third, to give a wide range of characters with a small number ofline-impulses, the system herein described being capable of printingfifty-four characters with a maximum of four line-impulses percharacter.

Fourth, to reduce to a minimum the number and functions of magnets. Bythis system the total number of magnets has been reduced to six(exclusive of relay-magnets.)

Fifth, to furnish a simple and reliable transmitting apparatus.

Sixth, to furnish a system in which the battery-circuits are allnormally open (1 6., when the system is inastate of rest) and one whichis capable of being organized and used for differential duplexing.

I will describe herein a system designed to accomplish the foregoingobjects and at tended with other advantages, as will'be hereinafterpointed out.

It has been heretofore proposed, instead of advancing the type-wheelstep by step, to

give it a continuous movement and provide it with a series of stops andwith mechanism for selecting any of the desired stops and for throwingit into position to arrest the typewheel. Such systems are for the mostpart very elaborate and complicated and involve the use of a largenumber of circuits and magnets. It has also been proposed to employ aseries of independent impelling devices,operated,respectively,byseparate magnets in various possiblecombinations, for positively rotating or pushing the type-wheel to anyone of its printing positions, according to the impelling device, orcombination of impelling devices, which is thrown into operation. Suchsystem is much simpler than the ordinary step by step or the synchronousmechanism; but its use puts considerable work upon the magnets, and itis necessary after printing each character to restore all parts to theirinitial positions before operating a combination for the next character.Other difficulties distinguishing my system from the foregoing Will behereinafter pointed out. It has also been proposed heretofore to impelthe type-wheel by a motor thrown into connection with the type-wheel bymeans of a magnet operated by a line-impulse, and to determine theextent of movement of the typewheel by a series of interacting stops,each controlled by a magnet adapted to be operated by a line-impulse. Inthe system here referred to the type-wheel, after each printing stroke,with all the displaced parts of the arresting mechanism, had to berestored to zero by a reverse movement of the wheelshaft. Threemaincircuits were required to work the various releasing, arresting, andrestoring mechanisms, and extra-strength currents were also utilized inthe operation of the system.

The present invention embraces a printingwheel whose point of arrestafter release is determined by a combination of stops, preferably threein number, each controlled by an impulse from the transmitting-station,and mechanism for operating the stops singly and in combination, so thatthe type-wheel can be arrested at any one of its printing positions. Theoperating -magnets therefore have only to fix the position of a stopwhich finally arrests the type-wheel, instead of impelling the shaft ofthe type-wheel. The latter can be connected by a frictional or slipconnection with any constantly-running motJr, so that it is verysensitive and prompt in action. Another gain in time is effected byreason of the fact that as soon as one printing stroke is made, orindeed while it is being made, the combination of stops for the nextcharacter can be set up. The wheel thus rotates constantly in onedirection, and not only is the time saved which is usually consumed inrestoring it to the starting-point, but all unison or retractingmechanism is dispensed with. This non-restoring type-wheel is one of theimport-ant and distinguishing features of my invention.

The capacities or ranges of action of the shiftable stops arerepresented by the powers of three, instead of by the terms of theseries of two, as heretofore. In other words, each stop may be regardedas having three possi ble positions--one a normal or resting posi tion,one a positive current position, the third a negative-current position.Thus with one such movable stop a wheel can be arrested (after beingstarted) at any one of three positions; with two such stops, at any oneof nine positions, and with three, at any one of twentyseven positions.A fourth stop and operating mechanism therefor would provide foreighty-one positions; but it is preferred to use only three stops and toarrange the type in two lines of twenty-seven each. Thus, with suitableshifting mechanism, the system provides for fifty-four characters andrequires only a maximum of four impulses for each character, one ofwhich impulses operates the shifting-magnet and the otherthree operatethe stop-magnets. The use of combinations made up of three elements andof shiftable stops each having three functional positions instead oftwo, as heretofore employed, is an important feature of the invention.

The invention embraces mechanism of a very simple character forproducing the printing stroke, and also improved transmitting mechanism,though, obviously, any transmitter capable of sending the positive andnegative impulses to line in the desired combination could be employed.

The invention further embraces certain other improvements in details andarrangements of devices and circuits, as will be hereinafter explained,and specifically pointed out in the claims at the end of thisspecification.

In the accompanying drawings, Figure 1 is a plan view of the receivingmechanism. Fig. 2 is a detail view of part of the operating mechanismfor the printing-shaft. Figs. 3, 4, and 5 are elevations, respectively,of the three stops. Fig. 6 is an end view of the receiving mechanism.Figs. 7 and 8 are respectively a plan and elevation of the transmittingmechanism. Fig. 9 is a diagrammatic view of the circuit arrangements andthe different elements of the mechanism.

A represents a printing-wheel of ordinary construction, having typearranged in two rows. Attached to the printing-wheel is a locking-wheelA, having a series of notches a, for purposes hereinafter explained, anda collar A These parts are all one piece and are feathered on the shaftB, so as to turn therewith, and also to be capable of movementlengthwise thereof to bring either of the rows of type into the printingposition. As shown, the right-hand row is in the printing position, andin the drawings all the parts are shown in their usual or normalposition.

On shaft B is a pulley b, loose thereon, but connected with a disk 1),fast thereon through a helical spring 0. Pulley b is driven by a cord 0,adapted to slip thereon when. the spring acquires a certain tension. Anyother suitable driving mechanism may be used, but that illustratedcauses the type-wheel. to start promptly when released and to turnquickly until arrested. The shift of the type-wheel is effected by ashift-magnet M, whose armature-lever m is forked at the end and carriespins engaging in a groove in collar A the construction being common andWell known for the purpose here in view.

M M M represent the three stop-magnets, which are shown aselectromagnetically-polarized magnets. The armature-lever m of the firststop-magnet is connected (in the same manner as described above forarmature-lcver m) with a sliding hub or collar (1, also feathered onshaft B.

Collar (Z carries the first of the stop-ar1ns D, and shaft B ends justbeyond this arm, from which point an independent shaft B extends in thesame line. On this shaft B is fixed the movable stop E, having threearms 1 2 3, (see Fig. 3,) each with an angular finger f f f on itsextremity. It will be observed that these fingers are in diii'erentvertical planes. Arm D, as shown, is resting against and is arrested byfinger f, the armature-lever m being in its intermediate position. Ifthe armature be attracted to the right, arm I) will move to the left,out of the path of finger f, and rotate until it encounters finger f Acorresponding movement in the opposite direction will bring the stop-armD into the path of finger f. These three fingers or stops are arrangedone hundred and twenty degrees apart, and by means of this first of theseries of stop mechanisms it is plain that by a positive impulse, anegative impulse, or no impulse at all, the type-wheel maybe made toassume one of three definite positions.

The other two of the series of stop-mechanisms are similar inconstruction and operation to the first, differing only in the locationof the stop-fingers. Magnet M controls a stop-arm D identical with arm Dand capable of assuming any one of three positions. Fingers'g g 9 (seeFig. 4) of stop 11 are in different vertical planes, and their angularpositions with reference to the shaft are such that they divide the arebetween any two fingers ff e., an arc of one hundred and twentydegreesinto three equal parts. Stop E is also fixed on a shaft B, whichbe gins where shaft B ends.

The third stop mechanism has the three fingers h h 7L2 of stop E adistance of one twenty-seventh of a circumference apart. Stop E which isthe last or final stop and fixes the ultimate point of arrest of thetypewheel, is not carried by a movable shaft, like stops E E but isfixed to a stationary support.

The action of the stop mechanism as a whole will now be readilyunderstood. For the purpose of explanation we will assume that positiveimpulses throw the armatures to the right and negative impulses to theleft. The first impulse of any combination operates the shift-magnet M.If this be a plus impulse there would be no shift inthe position shownin Fig. 1, since the armature is already attracted to the right-handpole of the magnet; but this first impulse (whether positive ornegative) starts the commutator, which successively brings thestop-magnets into circuit with a generator, as will presently beexplained. Consequently at the second impulse the circuit of magnet M isclosed. If this impulse'be positive, arm D shifts to the left, escapesfrom finger f, and shaft B rotates two-thirds of a revolution. If thedesired character happens to be just eighteen divisions from thestarting-point there will be no further impulses in the particularcombination transmitted, and consequently the second and third stopmechanisms will not be operated. In like manner a minus impulse throughmagnet M will permit the type-wheel to rotate one-third of a revolutionand arrest it at the end of nine divisions.

If the desired character be not at one of the three positions controlledby the first stop mechanism, one or both of the other mechanisms must becalled into operation. Thus, if the neXt impulse be plus, (the circuitof magnet H being then closed,) arm D will shift to the left, shaft Bwill be free to turn, the shaft B will turn as far as permitted by thefirst stop mechanism and two-ninths of a revolution farther. If thethird impulse be negative, the additional movement of the shaft B andtype-wheel will be one-ninth of a revolution. In like manner the thirdstop mechanism may allow a further revolution of one twentyseventh ortwo twenty-sevenths of a revolution, and by a single or combined actionof the several mechanisms the.

wheel can be turned to any desired one of twenty-seven angularpositions, the magnets having no work to do except to shift the stops.Conversely stated, for the shortest movements (one step or two)stop-magnet M alone is actuated, there being noimpulses at the timeswhen magnets M M are in circuit. For movements of grater range (four tonine) magnet M alone or M and M are actuated. For movements of thegreatest range magnet Malone, orin combination with one or both theother magnets, is actuated.

The mechanism for giving the printing stroke is also of very simpleconstruction. The printing-magnet M is brought into circuit, as will bepresently explained, just after the four impulses comprising a signalhave passed over the line. Armature M of this magnet throws the movablevmember is of an ordinary clutch into engagement with the relativelystationary member 7a, the latter being carried by a shaft which alsocarries a constantly-rotating pulley a, driven from any suitable motor.Member 70 of the clutch is feathered 011 the printing-shaft F, whichtherefore immediately begins to rotate. On the shaft is a disk G, havingan annular cam G, (see Fig. 2,) cut away or grooved at j.

In this groove a projection t' on the armature- I lever m rests when theparts are in their normal positions; but as soon as shaft F begins torevolve, cam G engages this projection, keeping the two parts of theclutch together, so that, although the circuit of magnet M isimmediately opened, the printing-shaft makes one complete revolution,being arrested when groove j once more comes opposite projection i andthe armature-lever can be retracted by its spring II.

N represents the printing-lever, pivoted at N and carrying the strap N(see Figs. 1 and 6,) which surrounds eccentric N on shaft F, so that atone revolution of shaft F the printing-lever is vibrated positively inboth directions. Lever N carries a wedge-shaped point or tooth n, whichat its upward movement enters one of the twenty-seven notches inlocking-wheel A, heretofore referred to, both momentarily arresting thetype-wheel and also bringing it accurately to the printing position.Lever N also carries a printing-pad at, over which passes a strip ofpaper M, which passes between feed-rolls N N The latter has aratchet-wheel n worked by a pawl n on the printing-lever N, and a detentn is provided to engage said ratchet-wheel. The type-wheels may be inkedby a brush 01.

Obviously the printing and paper feed mechanism can be of any suitabledescription.

Shaft F is also utilized to bring the armatures of the stop-magnets totheir normal or intermediate position, ready to be properly operated bythe next impulse which passes through the magnets. To this end the eX-tremity of each armature-lever m m m lies betweenthe faces of two cams OO on shaft F. Normally, as shown in the drawings, the

end of each lever is between the curved faces of the cams where thegroove or space between them is widest, and hence is free to move ineither direction. \Vhen an armature has been shifted, the curved face ofone of the cams restores it gradually to its normal position, as the camis rotated with shaft F.

It will be observed that as soon as tooth n releases the type-wheel(which it detains only for a small fraction of a second) the latter isfree to continue its march to the next resting-point, and that in themeantime the stops may be set or be in process of being set for the nextcharacter, there being no need of restoring the type-wheel to itsinitial position between successive printing operations, as in mostsystems. After a message has been printed, the type-wheel will simplycontinue to rotate until it reaches its initial point, since all thesteps will in that case return to their normal positions. (Shown isFigsl.) To fully understand the operation of the receiving mechanism itis necessary to refer to Fig. 9, in which the circuit arrangements andthe different elements of the mechanism are illustrateddiagrammatically.

The circuits of the shift-magnet M and stop-magnets M M M are controlledby an ordinary revolving switch-arm 's, which makes contact,successively, with the four contact-plates 10,11, 12, and 13 of acommutator. These magnets are in multiple-arc branches of a localbattery LB, magnet M being con nected with commutator-plate 10, M withplate 11, M with plate 12, and M with plate 13. The arbor p ofswitch-arm s also carries an escapement-wheel p, a second switcharm .9,and a pinion q. The main line L passes through the polarized relays R R,which may be of ordinary construction, and thence to ground. Mrepresents the polarized escapement-magnet which operates theescapement-lever p, the latter co-operating with the doubleescapement-wheel p to permit its shaft to complete one revolution ineight steps. Magnet M is a differential double-wound magnet, asindicated, the reason for which will presently appear.

It will be seen that my system requires the use of only six magnets inall (exclusive of the relay-magnets) and the work of each iscomparatively slight, permitting the use of a small amount of energy andtending toward certainty and promptness of action.

Pinion q drives a gear-wheel q, having twice as many teeth as saidpinion, and whose arbor carries the arm of a three-point switch. The armq" of a similar switch is carried by the shaft of a gear 91 driven froma pinion q (having half the number of teeth) on printing-shaft F. (See,also, Fig. 1.) Printing-magnet M is in the circuit of these switches,which circuit has a local battery LB.

Assuming that R is the positive relay and that the first impulse of asignal is plus, the following actions will occur: Armature of relay Rtouches its front contact 15 and a circuit is made from the plus pole ofbattery LB by wire 16, point 15, armature 7', wire 17, through onewinding of escapement-magnet M passing from one coil to the other bywire 18; thence by wire 19 to switch-arm s, commutator-plate 10,shift-magnet M, and by wire 20 to the battery LB.

The operation of the shiftqnagnet is understood, but the excitation ofthe escapementmagnet M draws lever 19' to one side, releasing the toothof the outer rim of the escapement-wheel p, permitting the latter andshaft 13 to turn one-eighth of a revolution. This leaves switch-arm .9still on plate 10; but as armature r at once returns to its back contacta circuit is closed, as presentlydescribed, through the auxiliarybattery L13 carrying a current in the opposite direction through theescapement-magnet, the effect being to vibrate arm 1) back to theposition shown in the drawings, turning shaft 13 another step andcarrying arm 3 over to plate 11 of the first stop-magnet M.

The circuit of the auxiliary battery above referred to is as follows:The rotation of shaft 19 has carried switch-arm s from the dead plate 1;of the auxiliary commutator to the first live plate c, (and it will beseen that there are eight of these plates, while the main commutator hasbut four.) Starting at the back stop of the positive relay, the circuitproceeds by wire 28 to switch-arm 5-, plate 2!, wires 30, 31, to theplus pole of the battery L13 by wire 32 to the back-stop of the negative relay R, over armature-lever 9", wire 27, to one winding(represented by the wire 22) of the differential escapement-magnet, backthrough the other winding 18 to wire 17 and armature-lever r to thepoint of beginning.

It may be observed that winding 18 of the magnet M is connected with thepositive relay and winding 29 with the negative relay, and that when thearmatures of both relays are on the back or resting contacts thecurrent, after passing through. one of the windings, returns through theother, (the currents being in opposite directions in the reverselywoundcoils, thereby reinforcing each other,) and that only when onerelay-armature is on its front contact does the local battery LB comeinto circuit through one of the stopmagnets. The same movement of theescapement-wheel which carried arm 3 to plate 11 carried arm 3 to thesecond live plate 11 which is connected to the opposite pole of theauxiliary battery L13 If now no mainline impulse immediately follows thefirst, as is the case when the first stop mechanism in the combinationis not to be shifted either to the right or left, the auxiliarycommutator and battery are in position to work the escapement-arm, thusperforming the function of a line-impulse. That case will be consideredpresently, and it will first be assumed that in the combination beingtransmitted another impulse immediately follows the first, and that itsCsign is minus. In such case the negative relay R responds, attractinglever 9" to front stop 25. The circuit can then be traced from point 25by wire 26 to battery LB, thence by wire 20 through magnet M, by wire 26to commutatonplate 11, through switch-arm 8, wire 19, winding 29 ofescapement-magnet M wire 27 and armaturelever r to the point ofbeginning. The current through the escapement-magnet is in this case inthe opposite direction to that of the current produced by the action ofrelay R but as windings 18 and 29 are reversed, as already stated, theeffect is the samenamely, to draw lever 19 from engagement with theouter row of teeth of wheel 19 into engagement with the inner row ofteeth. Shaft 19 thus turns another step, bringing arm 3 into engagementwith plate 0 and the auxiliary battery is brought into operation, asbefore, returning lever 13 and moving arm 8 to plate 12. Thus if thecombination consists of four line-impulses, of whatever sign, theescapement-arm is actuated in one direction by currents from the localbattery LB and returned by currents from the auxiliary battery LB untilshaft 19 has completed a revolution. The system, however, provides thatthe omission of impulses shall have a significance in the code ofsignals. In other words, the signals are all compounded of threeelements namely: first, plus impulses; second, minus impulses; third, noimpulses. When, therefore, in the transmission of a signal, the noimpulse element is used the auxiliary commutator comes into play toperform the usual function of line-impulse and work theescapement-magnet forward. IVhat actually hap pens at such time is thatthere is an extra long interval between the signals, an interval equalto the usual duration of an impulse plus the usual duration of twobreaks. It will be seen that after a line-impulse has worked theescapement-arm and the auxiliary commutator has returned it, theswitch-arm s will be in contact with one of the plates 12 12* U, whichare all connected with the positive pole of auxiliary battery L13 whilethe plates 0) t which send the current for returning theescapement-arm,are all connected with the opposite pole of the battery.Hence, in case no impulse immediately follows, the first auxiliarybattery sends a current through the escapement-magnet in a directionoppo site to that whose course was traced above, producing the desiredeffect. The auxiliary commutator always tends to perform this function,but when impulse immediately follows impulse over the main line (thebreaks being relatively short, as explained, the current from theauxiliary battery does not act, since its circuit is broken at one orthe other of the relay-armatures. In case of the extralong interval dueto the omission of an impulse, the auxiliary battery has abundant timeto reverse itself through the escapementmagnet and to shift switch arm 8from one plate to the next. In case of two omissions of line-impulsestogether, the auxiliary commutator will repeat its action. In the casewhere the type-wheel is already in the position to print the desiredcharacter, the combination consists of but a single impulse, the otherthree elements being represented by blanks or no impulses. In such casethe first impulse, whichoperates the shift-magnet, starts theescapement-shaft, and the auxiliary commutator works it entirely around.Thus the escapement-shaftp makes one complete revolution for eachcombination, however composed.

At the end of each revolution the circuit of the printing-magnet m isclosed through its battery LB, through the operation of the three-pointswitches already referred to. I will now describe their operation: Arm ghas two contact-strips 36 37, and arm (1 has two similar strips 38 39.Contacts 36 and 38 are connected by wire 40 and strips 37 and 39 by wire41. A wire 35 runs from one pole of battery LB to arm 1 and another wire42 runs through magnet m to arm (1 In the position shown in Fig. 9 thecircuit of battery LB is open. When, however, pinion q has made acomplete revolution with shaft 19 arm (1 turning in the direction of thearrow, will have made a semi-revolution and come into contact with strip37. This completes a circuit, as follows: from minus pole of battery LB,by wire 35, to arm g to strip 37; thence by wire 4], strip 39, arm q,and wire 42, through magnet M back to battery LB. The printing-shaft nowoperates as above described, and in doing so it turns arm q -onehalf arevolution into contact with strip 38, which is now out of circuit byvirtue of the fact thatits companion strip 36 is no longer in contactwith arm g When arm (1 makes another semi-revolution, which it does whenthe next signal has passed over the line, it again touches strip 36,closing the circuit of printing-magnet M*, which is immediately brokenagain by the movement of printingshaft F. Thus the switch-arms of thetwo three-point switches operate in alternation, one to close thecircuit of the printing-magnet at each rotation of the escapementshaftand the other to break the circuit at each each rotation of theprinting-shaft.

' For producing the required combinations of impulses I have devised asimple form of transmitting apparatus. (Illustrated in Figs. 7 andSandby diagram in Fig. 9.) This transmitter is of the keyboard type, and byits operation the depression of any of the keys has the effect ofsending to line from main battery MB the combination of impulsescorresponding to the character which such key represents. For thispurpose an ordinary commutator, comprising a switch-arm S and fourplates or segments 50 51 52 53, are provided, These plates arerespectively connected with the four plates (51 62 63 of a pole-changingapparatus, while the switcharm S is connected to line L. Adjacent tothese plates are two conducting-bars 5455. The former connects with thepositive pole of battery MB and the latter with its negative pole, whilea wire 56 runs from the middle of thebattery' to ground. Between thebars 54 55 is an insulating-strip 57. Each contactplate has a movablecontact-maker, designated, respectively, 70 71 72 7 3, these beingtheThe contact-points nor- S, driven by aconstantly-running cord which Thearm is engages it with light friction. normally held from rotation by astop-lever 65, engaging a finger 66, connected with the switch-arm. Thislever has a cross-bar 67 extending under all the key-levers U, so thatthe depression of any key releases the switcharm, permitting it to makeone revolution, sending to line a combination of four elements, thecharacter of which depends on the positions of the four pole-changers.

The actuating mechanism for the polechangers Will be understood byreference to Figs. 7 and 8. Each key-lever U carries two uprights U Ueach of which has projections 10 for operating the polechangers. It willbe understood that arrangement of these opcrating projections differsforeach key. Each of v the pole-changers is carried by a tilting frame TT T These frames are pivoted on shaft t and have each two parallelhorizontal cross-bars t t extending across the apparatus, so as to be inthe range of all the operating projections w. tion of one key U willsuffice for all. The key shown in elevation in Fig 8 is supposed to havebeen last depressed and returned by its spring. In this action theprojection 10 has depressed frame T, carrying pole-changer 70, whichcontrols the first line -impulse, which is to actuate the shift magnetM. Hence the first impulse is minus. Frame T has been tilted in theopposite direction by ro'ection w sendin a lus im )ulse to line throughcommutator-strip 51. Frames T T have not been tilted at all, thepositions of the projections w 20 and 10 20* being such as merely totouch the cross-bars 25 t of their respective frames if the latterhappen to be in a horizontal position. Hence no current goes to linethrough pole-changers 72 73, and therefore the signal transmitted bythis key consists of the elements minus, plus, zero. The projections 1020" act as restorers in case frames T T have been shifted by thepreceding key. This obviates the necessity of providing special meansfor returning the frames after each key has been struck, since each keypositively sets its combination of pole-changers in whatever position itmay find them. The key-levers, after being depressed and released, areat once restored by their springs y, and not detained in their depressedcondition until the commutator has The explanation of the acmade acomplete revolution. Spring-restoring mechanism for the pole-changersbeing dispensed with and positive setting devices substituted thereforrenders it unnecessary to keep the keys depressed for a definite time,since the pole-changers will remain wherever placed until shifted by thedepression of another key.

The foregoing description has set forth with minuteness the details of asystem embody ing the principles of the invention; but it must beunderstood that this is done only for the purpose of explaining fullyone way in which the invention may be carried into effeet and not withthe object of giving undue importance to details, which may be variedand modified within wide limits.

The invention involves certain features which are believed to bebroadlynew, and therefore it is designed to cover them broadly. For example, notype-wheel system has heretofore been devised, so far as I am aware, inwhich the combinations representing different characters of the code aremade up of three elements. All similar systems heretofore have utilizedonly the powers of two elements represented by plus and minus impulses.

The use of controlling mechanisms for the printing devices each havingthree functional positions is also believed to be new. This feature ofthe invention can be applied by one skilled in the art to mechanismwidely different from that described herein.

Having thus described my invention, what I claim as new is- 1. In atelegraph system, and in combination with suitable receiving apparatusadapted to respond to signals compounded of three impulses, representedby plus impulses, minus impulses, and no-impulses, a transmittingapparatus comprising a generator, a series of pole-changers andmechanism for shifting each pole-changer to connect either pole of thegenerator to line, or to leave the line open,thus sending to linesignals compounded of plus impulses, minus impulses, and no impulses, asset forth.

2. In a telegraph system, the combination with receiving apparatusadapted to respond to signals compounded of three elements representedby plus impulses, minus impulses, and no impulses, of transmittingapparatus comprising a commutator, pole-changers con.- nectedrespectively with the successive plates of said commutator, a generator,and mechanism for operating the pole-changers to connect either pole ofthe generator to line through the several commutator plates, or todisconnect it, as set forth.

3. The combination with the telegraphic receiving apparatus adapted torespond to signals compounded of three elements, as specified, of atransmitter comprising a commutator, pole-changers, one for eachcommutator plate and adapted to assume any of three positions, agenerator, and circuits and connections whereby a pole-changer in oneposition connects the positive pole of the generator to its commutatorplate, in the second position connects the negative pole with saidplate, and in the third disconnects said generator and plate,substantially as described.

4. The combination in a telegraphic transmitter, of the commutator, thepole-changers, one for each commutator plate, carried each by a movablesupport, and key-levers having actuating devices, different for eachlever, for positively setting all the pole-changers from whateverposition, normal or otherwise they may be in, substantially asdescribed.

5. The combination, in a telegraphic transmitter, of a commutatornormally held stationary by a detent, a motor for said commutator,pole-changers, having each three functional positions, there being onepole-changer for each commutator plate, key-levers and mechanismactuated thereby for operating said pole changers and for releasingsaidcommutator from its detent permitting it to make one revolution, as setforth.

6. In a telegraph receiver, the combination with signal receivingdevices including a shaft and means for rotating the same always in onedirection, of a series of interlocking stop-mechanisms whereby the pointof arrest of said shaft is determined, said stop-mechanisms comprisingarms rotatable in the direction of rotation of said shaft, andelectromagnets controlling the several stop-mechanisms, substantially asdescribed.

7. In a telegraph receiver, the combination with a non-restoringtype-wheel, and means for rotating the same in one direction only, ofstop-mechanism comprising a series of interlocking arms, carried each byrotatable supports, and electro-magnetic controlling devices, wherebythe stops can be shifted axially to arrest the said shaft at any desiredpoint, substantially as described.

8. In a telegraph-receiver, the combination with a shaft and means forrotating the same, of a series of interlocking and independently movablestops, having each three functional positions, and electro-magneticmechanism, whereby the stops are independently controlled, substantiallyas described.

9. The combination with the type-Wheel and means for rotating the same,of a series of stop-mechanisms, each comprising three stop fingers on arotatable support, an engaging arm on an independent support and meanscontrolled by an electro-magnet for shifting the arm from the path ofone stop into that of another, substantially as described.

10. The combination with the type-wheel and means for rotating the same,of a series of stop mechanisms, each comprising three stop-fingers indifferent planes and carried by a rotatable support, an engaging arm onan independent support, and an electro-magnet and connections forshifting the arm to one position when influenced by a positive current,and to another when influenced by a negative current, said arm occupyinga third position when the magnet is not excited, substantially asdescribed.

11. The combination with the printingwheel, having two rows of type, andthe motor, of the shift magnet for shifting the printing-wheellengthwise of its shaft and a series of interlocking stop-mechanisms,having each a controlling magnet, whereby the point of arrest of theWheel is determined, substantially as described.

12. The combination with the printing wheel, and motor, of a series ofinterlocking stop-mechanisms, for determining the arrest of the wheel,each stop-mechanism being actuated by a lever connected with thearmature of a magnet, a printing shaft, printing mechanism actuatedthereby, and restoring devices for said armature levers actuated fromsaid printing shaft, substantially as described.

13. The combination with the type-wheel, a series of magnets controllingstop mechanism therefor, a commutator for bringing the stop-magnetssuccessively into circuit with a divided local battery, an auxiliarybattery, a differentially wound escapement magnet having two similarreversely wound coils in circuit respectively with the two parts of saidlocal battery, both said coils being serially connected in the circuitof said auxiliary battery, relays in the main line respondingrespectively to positive and negative impulses and controlling thecircuit connections of said local battery, and an auxiliary commutatorin circuit with said auxiliary battery, substantially as described.

14. The combination of the type-wheel, a series of stop-magnets,mechanism controlled thereby for determining the range of movement ofsaid wheel, a commutator to the plates of which said magnets arerespectively connected, a printing magnet and mechanism controlledthereby, a switch operated by the commutator shaft to close the circuitof the printing magnet when said commutator has completed a revolution,and a second switch operated by said printing shaft to break saidcircuit when said shaft has completed a revolution, substantially asdescribed.

In testimony whereof I have signed this specification in the presence oftwo subscribing witneses.

JONATHAN W'OODBRIDGE.

Witnesses PHILIP MAURO, REEVE LEWIs.

